Asphalt-based roofing materials, such as roofing shingles, roll roofing, and commercial roofing, are installed on the roofs of buildings to provide protection from the elements, and to give the roof an aesthetically pleasing appearance. Typically, the roofing material is constructed of a substrate such as a glass fiber mat or an organic felt, an asphalt coating on the substrate, and a surface layer of granules embedded in the asphalt coating.
A common method for the manufacture of asphalt shingles is the production of a continuous sheet of asphalt material followed by a shingle cutting operation which cuts the material into individual shingles. In the production of asphalt sheet material, either a glass fiber mat or an organic felt mat is passed through a coater containing hot liquid asphalt filled with limestone to form a tacky, asphalt coated sheet. Subsequently, the hot asphalt coated sheet is passed beneath one or more granule applicators which discharge protective and decorative surface granules onto portions of the asphalt sheet material.
In certain types of shingles, it is especially desired that the shingles define a sufficiently wide area, often known in the industry as the “nail zone,” in order to make installation of roofs using shingles, such as laminated shingles, more efficient and secure. One or more lines or other indicia painted or otherwise marked longitudinally on the surface of the shingle may define such a nail zone. It is especially desired that the shingles define a nail zone that guides installers in the placement of nails.
Additionally, shingles may experience lift in high wind situations. This lift may be exacerbated if the shingle tabs are not sealed or adhered to the shingle below. Therefore, there is also a need for shingles that have a sufficiently high nail pull-through value so that the installed shingles have improved performance in high wind situations.